Pavelec stopped 36 shots in only his third career start, while Kovalchuk scored his eighth goal in his last four games in the Thrashers' 4-1 victory.
"I'm happy because we need the points," said Pavelec, a 20-year-old from the Czech Republic. "It's not about how many goals you score or how many saves you make, it's about the two points."
Pavelec began the season with the AHL's Chicago Wolves before being recalled when starting goalie Kari Lehtonen sustained a groin injury. After making two appearances in relief, he made his first career start in a 6-4 victory at Tampa Bay Saturday and started again Tuesday when the Thrashers beat Washington 2-1 in overtime.
"We know him pretty well," Thrashers general manager and interim coach Don Waddell said. "We drafted him only a couple of years ago. He was good in training camp, he played well in exhibitions. We have a lot of confidence in him."
Pavelec was particularly strong in the second period, when he shut out Florida on 14 shots. His best save came late in the period, when he snagged Olli Jokinen's wrist shot from close range with his glove.
"I just hoped he shot for the glove side because I had opened the blocker side," Pavelec said. "It was a good save."
Kovalchuk scored his NHL-leading 14th goal on a power play at 8:30 of the third period to give Atlanta a 3-1 lead. He took a feed from Hossa in the slot and fired a wrist shot past Vokoun.
"The goalie, he didn't see it when I shot it," Kovalchuk said. "It was a great play for everybody."
Kovalchuk played despite leaving Tuesday's game in the second period because of back spasms. He had one goal in that game, following three-goal games at Ottawa and Tampa Bay.
Kovalchuk said after Friday's game his back felt fine, and there certainly didn't seem to be any problem on his goal.
"He scored a great goal," Waddell said. "It was a great feed from Hossa. Once Ilya gets it in the slot there, he doesn't make too many mistakes. He's going very good, he's shooting the puck and he's also doing a good job defensively."
Nathan Horton scored for the Panthers.
Tomas Vokoun, starting in net for the 10th consecutive game, made 23 saves.
"We have to put it all together," Vokoun said. "We haven't been able to do that. Some nights yes and some nights no. That's why we have more losses than wins."
After Kovalchuk's goal, Hossa added to the lead with a goal on a 5-on-3 power play with 5:16 left in the third.
Atlanta led 1-0 going into the third period before Horton tied the game 18 seconds in. His sixth goal of the season, but only his second in his last 10 games, came after he took a feed from Jokinen from behind the net and fired a wrist shot under the crossbar.
The Thrashers regained the lead at 3:22, when Thornburn scored his first of the season. Mark Popovic fired a shot through traffic from the point and the rebound slid across the front of the net to a wide-open Thorburn.
"I thought we dominated for the first two periods," Florida coach Jaques Martin said. "I think we doubled them in chances. Their goalie made some good saves and kept them in. We gave the goal at the end of the second, then came back to tie it. I thought we had some good pressure."
Florida C Brett McLean suffered a broken right hand blocking a shot in the second period. ... Florida recalled D Jassen Cullimore from Rochester of the AHL, and sent down RW Anthony Stewart. Signed Oct. 26, Cullimore was sent to Rochester for a two-week conditioning stint. ... Panthers D Bryan Allen missed his second consecutive game because of a concussion he sustained Monday night in a game against Tampa Bay. ... Holik's first assist was the 400th of his career. ... Kozlov extended his point streak to six games. ... Florida entered the game with the league's best power play at home and Atlanta the worst overall penalty killing, but the Panthers had only one power-play opportunity in the game.